1. Field of the Invention
The present invention relates to a recording material suitable for ink-jet recording using a liquid ink such as an aqueous ink, an oil-based ink, and a solid ink which is solid at a normal temperature and is subjected to printing by being melted and liquefied, and method for preparing the same. More particularly, the present invention relates to an ink-jet recording sheet excellent in ink receiving ability, and method for preparing the same.
2. Description of the Related Art
Recently, with rapid development of information industries, various information processing systems have been developed, and recording methods and apparatuses suitable for these information systems also have been developed, and all of these have been put into practice.
Among the aforementioned recording methods, an ink-jet recording method come to be widely used, in offices and for home-use since many kinds of recording materials can be recorded thereby, and hardware (apparatuses) thereof is relatively inexpensive and compact, and quietness thereof is excellent.
In addition, with recent enhancement of resolution of ink-jet printers, it has also become possible to obtain “photorealistic” high image quality recorded materials. Additionally, with development of hardware (apparatuses), various types of recording sheets for ink-jet recording have been developed.
Properties required for the aforementioned recording sheets for ink-jet recording are generally (1) quick-drying (high ink absorbing rate), (2) appropriate and uniform diameter of ink dots (no blurring), (3) good granularity, (4) high complete-roundness of dots, (5) high color density, (6) high chroma (no dullness), (7) good light fastness, gas resistance and water resistance of printed portions, (8) high whiteness of a recording sheet, (9) good shelf stability of a recording sheet (no occurrence of yellowing coloration by long term storage, no blurring of an image by long term storage), (10) little deformation, and good dimensional stability (sufficiently small curling), (11) good hardware running properties, and the like. For utilizing a photographic glossy paper used for the purpose of obtaining the photorealistic high image quality recorded material, in addition to the aforementioned properties, glossiness, surface smoothness, photographic paper-like texture similar to that of a silver salt photograph and the like are also required.
As an ink-jet recording sheet satisfying the aforementioned requirements, there are known a sheet, in which a solution containing inorganic fine particles, a mordant, a water-soluble resin such as PVA, and a hardener for the water-soluble resin is coated on a support to form a colorant receiving layer (for example, the following Japanese Patent Application Laid-Open (JP-A) No. 12-211235 (paragraph 0055-0057)), and a sheet, in which a solution containing inorganic fine particles, a metal compound, and a water-soluble resin such as PVA is coated on a support and, before complete drying of a coated layer, a solution containing a hardener for the water-soluble resin is applied to the coated layer to form a colorant receiving layer (for example, see the following JP-A No. 2001-334742).
The colorant receiving layer in the ink-jet recording sheet described in JP-A No. 12-211235 (paragraph 0055-0057) is obtained by coating and drying a coating solution containing gas phase method silica, a cationic polymer having a structural unit of a polydiallylamine derivative (dimethyldiallylammonium chloride polymer), PVA and boric acid, however, with this ink-jet recording sheet printing density and glossiness of an image is low.
The colorant receiving layer in an ink-jet recording sheet of JP-A No. 2001-334742 is a layer obtained by coating a coating solution including inorganic fine particles (e.g. gas phase method silica having an average primary particle diameter of 20 nm or less), a water-soluble resin (e.g. PVA) and an at least divalent water-soluble metal salt on a support and, at the same time as coating, or before the coated layer shows a falling rate of drying, applying a solution containing a cross-linking agent which can cross-link the water-soluble resin (e.g. borax or boric acid) to harden the layer. Thus obtained colorant receiving layer can prevent cracking, however there was a problem that the printing density of an image is low, and the stability of the coating solution containing the water-soluble metal salt is not sufficient.
As a mordant for fixing a dye in an ink receiving layer, there is known an inorganic mordant such as a polyvalent metal salt (for example, see the following JP-A Nos. 2002-172850 or 2002-274013) in addition to the cationic polymer described in the aforementioned JP-A No. 12-211235 (paragraphs 0055-0057).
An ink receiving layer in JP-A No. 2002-172850 contains inorganic fine particles, polyvinyl alcohol, at least two kinds of a cationic polymer having a quaternary ammonium base, and a compound having a zirconium or aluminium atom (except for zirconium oxide and aluminium oxide) in a molecule, and reduces blur and improves water resistance of a water-soluble dye during storage after printing without deteriorating bronzing.
In addition, a colorant receiving layer in JP-A No. 2002-192830 is characterized in that it contains polyvinyl alcohol, a cationic polymer, and a compound having a zirconium or aluminium atom (except for zirconium oxide and aluminium oxide), and a film surface pH of the surface of the ink receiving layer after printing with an ink-jet printer is 4 to 6, and reduces blur and improves water resistance of a water-soluble dye during storage after printing without deteriorating bronzing.
Further, a colorant receiving layer in JP-A No. 2002-274013 contains inorganic fine particles, a hydrophilic binder, a compound A containing a zirconium atom or an aluminium atom (except for zirconium oxide and aluminium oxide) in a molecule, and a compound B which is different from the compound A and contains a polyvalent metal atom in a molecule, at 0.1 to 10 mole % of the compound A, and suppresses occurrence of blur and improves the water resistance of an image when a printed image using a water-soluble dye is stored, without deteriorating bronzing.
When an ink receiving layer is formed according to the same manner as that of JP-A No. 2001-334742 using this inorganic mordant described in JP-A No. 2002-172850or JP-A No. 2002-274013, cracks do not occur in the ink receiving layer, however sufficient glossiness and printing density can not be obtained. Further, stability of a solution is not improved.